JP2019029487A - Imprint apparatus, imprint method and article manufacturing method - Google Patents

Abstract

To provide a technology that is advantageous for reducing breakage of a reference plate.SOLUTION: An imprint apparatus forms a pattern on a substrate by contacting an imprint material arranged on the substrate with a mold and hardening. The imprint apparatus comprises: a mold holding part that holds the mold; a substrate holding part that holds the substrate; a dispenser that arranges the imprint material on the substrate; and a scope that images a mark. The substrate holding part includes a reference plate that has a reference mark imaged by the scope, the dispenser is arranged in a first direction being seen from the mold holding part, and the reference plate is arranged between a virtual straight line that is parallel to a second direction being perpendicular to the first direction and that passes through a center of the substrate holding part and an end part of the substrate holding part in a side of the first direction being seen from the virtual straight line.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an imprint apparatus, an imprint method, and an article manufacturing method.

  The imprint apparatus forms a pattern made of a cured product of an imprint material on the substrate by bringing a mold into contact with the imprint material disposed on the substrate and curing the imprint material. The imprint apparatus includes a reference plate having a reference mark on a substrate holding unit that holds the substrate. In the calibration step, for example, the relative position between the mold mark and the reference mark is measured by the alignment scope, whereby the relative position between the mold and the substrate holder can be obtained. Patent Document 1 describes an imprint apparatus having a stage reference mark provided on a wafer stage.

Japanese Patent No. 5451450

  In the imprint process, after the mold is brought into contact with the imprint material on the substrate and cured, the mold can be charged when the cured imprint material and the mold are separated. In the reference plate, the base material may be made of an insulator such as quartz, and the reference mark may be made of a conductive reflective film such as chromium. Conventionally, in a series of sequences in which a pattern is formed for each of a plurality of shot regions of a substrate, a discharge occurs between the mold and the reference plate because the reference plate passes under the charged mold. Could be damaged.

  The present invention has been made with the above problem recognition as an opportunity, and an object thereof is to provide an advantageous technique for reducing the breakage of the reference plate.

  One aspect of the present invention relates to an imprint apparatus that forms a pattern on a substrate by bringing the mold into contact with an imprint material disposed on the substrate and curing the mold, and the imprint apparatus includes the mold A mold holding unit that holds the substrate, a substrate holding unit that holds the substrate, a dispenser that disposes an imprint material on the substrate, and a scope that images a mark, and the substrate holding unit includes the scope The dispenser is arranged in a first direction when viewed from the mold holding part, and the reference plate is parallel to a second direction perpendicular to the first direction. And an imaginary straight line passing through the center of the substrate holding part and an end of the substrate holding part on the first direction side when viewed from the imaginary straight line.

  According to the present invention, an advantageous technique is provided for reducing the damage of the reference plate.

The figure which shows the structure of the imprint apparatus of one Embodiment of this invention. The figure explaining the calibration performed using a reference mark. The figure explaining the calibration performed using a reference mark. The figure explaining the imprint process (pattern formation process) with respect to one shot area | region by an imprint apparatus. The figure explaining the change of the relative position of the dispenser in the imprint apparatus of a comparative example, a type | mold, and a reference | standard plate. The figure explaining the change of the relative position of the dispenser, type | mold, and reference | standard plate in the imprint apparatus of 1st Embodiment. The figure which illustrates arrangement | positioning of a reference | standard plate. The figure which illustrates the structure of a reference | standard plate. The figure which shows the movement of the electric charge in a reference | standard plate typically. The figure which shows one example of a structure of the reference | standard plate of 2nd Embodiment. The figure which shows the other example of a structure of the reference | standard plate of 2nd Embodiment. The figure which shows the structure of the reference | standard plate of 3rd Embodiment. The figure which shows an article manufacturing method.

  Hereinafter, the present invention will be described through exemplary embodiments with reference to the accompanying drawings.

  FIG. 1 shows a configuration of an imprint apparatus 100 according to an embodiment of the present invention. The imprint apparatus 100 contacts the mold M with the imprint material R disposed on the substrate W, and then cures the imprint material R to cure the imprint material R on the substrate W. A pattern is formed.

  As the imprint material, a curable composition (which may be referred to as an uncured resin) that cures when energy for curing is applied is used. As the energy for curing, electromagnetic waves, heat, or the like can be used. The electromagnetic wave can be, for example, light having a wavelength selected from a range of 10 nm to 1 mm, for example, infrared rays, visible rays, ultraviolet rays, and the like. The curable composition may be a composition that is cured by light irradiation or by heating. Among these, the photocurable composition that is cured by light irradiation contains at least a polymerizable compound and a photopolymerization initiator, and may further contain a non-polymerizable compound or a solvent as necessary. The non-polymerizable compound is at least one selected from the group consisting of a sensitizer, a hydrogen donor, an internal release agent, a surfactant, an antioxidant, and a polymer component. The imprint material can be disposed on the substrate in the form of droplets or in the form of islands or films formed by connecting a plurality of droplets. The viscosity of the imprint material (viscosity at 25 ° C.) can be, for example, 1 mPa · s or more and 100 mPa · s or less. As the material of the substrate, for example, glass, ceramics, metal, semiconductor, resin, or the like can be used. If necessary, a member made of a material different from the substrate may be provided on the surface of the substrate.

  The substrate W is, for example, a silicon wafer, a compound semiconductor wafer, or quartz glass. The substrate W has a mark 11. The mold M can be made of, for example, quartz or resin. The mold M can include a pattern region Mp having a pattern to be transferred to the imprint material R on the substrate W. The pattern region Mp is provided, for example, in the mesa portion MS, and the mesa portion MS can be surrounded by the peripheral region PR. The mesa portion MS protrudes from the peripheral region PR. The mold M has a mark 10. The mark 10 can be provided in the pattern region Mp, for example.

  In this specification and the accompanying drawings, directions are shown in an XYZ coordinate system in which a direction parallel to the surface of the substrate W is an XY plane. In the XYZ coordinate system, the directions parallel to the X, Y, and Z axes are the X, Y, and Z directions, respectively, and rotation around the X axis, rotation around the Y axis, and rotation around the Z axis are θX and θY, respectively. , ΘZ. The control or drive related to the X axis, Y axis, and Z axis means control or drive related to the direction parallel to the X axis, the direction parallel to the Y axis, and the direction parallel to the Z axis, respectively. The control or drive related to the θX axis, θY axis, and θZ axis relates to rotation around an axis parallel to the X axis, rotation around an axis parallel to the Y axis, and rotation around an axis parallel to the Z axis. Means control or drive. The position is information that can be specified based on the coordinates of the X axis, the Y axis, and the Z axis, and the posture is information that can be specified by the values of the θX axis, the θY axis, and the θZ axis. Positioning means controlling position and / or attitude. The alignment may include control of the position and / or attitude of at least one of the substrate and the mold.

  The imprint apparatus 100 includes a substrate holding unit 5 (substrate stage) that holds the substrate W, a substrate driving mechanism 20 that drives the substrate W by driving the substrate holding unit 5, a mold holding unit 6 that holds the mold M, and A mold driving mechanism 30 for driving the mold holding unit 6 may be provided. The substrate drive mechanism 20 and the mold drive mechanism 30 constitute a relative drive mechanism that drives at least one of the substrate W and the mold M so that the relative position between the substrate W and the mold M is adjusted. The adjustment of the relative position by the relative drive mechanism includes a drive for contact of the mold M with the imprint material on the substrate W and separation of the mold M from the cured imprint material (cured material pattern). . The substrate driving mechanism 20 moves the substrate W into a plurality of axes (for example, three axes of X axis, Y axis, and θZ axis, preferably six axes of X axis, Y axis, Z axis, θX axis, θY axis, and θZ axis). ). The mold drive mechanism 30 includes a mold M having a plurality of axes (for example, three axes of Z axis, θX axis, and θY axis, preferably six axes of X axis, Y axis, Z axis, θX axis, θY axis, and θZ axis). ). The mold holding unit 6 may include a shape correction mechanism that deforms the mold M in accordance with the shape of the shot region of the substrate W.

  A reference plate 7 having reference marks 12 and 13 is disposed on the substrate holding part 5. The reference plate 7 can be used in calibration of the imprint apparatus 100. The base material of the reference plate 7 is not easily deformed by heat and can be made of a stable material (for example, quartz). The reference marks 12 and 13 can be configured by a portion where a base material is covered with a conductive material film (for example, a chromium film) that reflects light and a portion where the base material is exposed. Alternatively, the reference marks 12 and 13 may be configured by a portion where the base material is covered with an insulating material that reflects light and a portion where the base material is exposed.

  The imprint apparatus 100 can further include a curing unit 1, an alignment optical system 2, an observation optical system 3, a dispenser 8, and a control unit CNT. The curing unit 1 can cure the imprint material R by irradiating the imprint material R with curing energy for curing the imprint material R on the substrate W (in this example, light energy such as ultraviolet rays). The mold M can be made of a material that transmits the curing energy. When the curing unit 1 generates light energy as curing energy, for example, a high-pressure mercury lamp, various excimer lamps, excimer lasers, light emitting diodes, or laser diodes can be employed as the light source.

  The alignment optical system 2 is used to measure the relative position between the shot area of the substrate W and the mold M. Based on the relative position between the shot area of the substrate W and the mold M, at least one of the substrate drive mechanism 20 and the mold drive mechanism 30 is driven, and the shot area of the substrate W and the mold M are aligned. At this time, the shape correction mechanism provided in the mold holding unit 6 can also be driven.

  The alignment optical system 2 includes at least one scope 2a for imaging the mark 11 on the substrate W, the mark 10 on the mold M, and the reference marks 12 and 13 on the reference plate 7, and preferably a plurality of scopes 2a. The relative position between the shot region of the substrate W and the mold M is obtained by processing an image obtained by imaging. Each scope 2a can be driven in the X-axis direction and the Y-axis direction according to the position of the mark M of the mold M or the mark 11 of the substrate W. Furthermore, each scope 2a may be configured to be able to drive in the Z-axis direction for focus adjustment, or may incorporate a focus adjustment mechanism. The alignment optical system 2 can further include a plurality of optical elements 21, 22, 23, and 31. In this example, the plurality of optical elements 21, 22, 23, and 31 constitute a relay optical system, and images of the marks 10 and 11 are formed on a plane conjugate with the surface of the substrate W.

  When the mold M is exchanged, as shown schematically in FIG. 2, the alignment optical system 2 is used to align the mark 10 of the mold M and the alignment mark among the plurality of marks on the reference plate 7. The relative position to 12 is measured. Thereafter, the relative position between the mold M and the substrate holder 5 can be controlled based on the relative position obtained by measurement.

  Further, the relative position between the mark 10 of the mold M and the mark 11 of the substrate W can be measured using the alignment optical system 2. Each scope 2a of the alignment optical system 2 includes the mark M of the mold M and the mark 11 of the substrate W if the placement error of the mold M, the placement error of the substrate W, the placement error of the mark 11 of the substrate W, and the like are within allowable ranges. Can be stored in the field of view at the same time. Therefore, based on the relative position between the mark 10 of the mold M and the mark 12 of the reference plate 7, the mark 11 provided in the shot region of the substrate W held by the substrate holding unit 5 is used for the scope 2 a of the alignment optical system 2. It can fit in the field of view.

  The observation optical system 3 is an optical system for observing the entire shot area of the substrate W. The observation optical system 3 is also a scope that images a mark. The observation optical system 3 can be used for observing the state of the imprint process. The imprint processing state includes, for example, a contact state between the imprint material R and the mold M on the substrate W, a filling state of the imprint material R into the recesses constituting the pattern of the mold M, and the top of the substrate W. It may be a state of separation from the mold M from the cured imprint material R or the like.

  Although it is desirable that the optical axis of the observation optical system 3 and the optical axis of the alignment optical system 2 are the same, a certain amount of error may exist between them. Accordingly, the observation optical system 3 can be calibrated. Calibration of the observation optical system 3 can be performed using the reference plate 7. When adjustment of the observation function (for example, light amount adjustment or visual field adjustment) is performed, as schematically shown in FIG. 3, the reference mark 13 for the observation optical system 3 among the plurality of marks on the reference plate 7 is the observation optical system. The substrate holding unit 5 can be driven by the substrate driving mechanism 20 so as to fall within the field of view 3. In FIG. 3, the observation optical system 3 is adjusted with the mold M held by the mold holding unit 6, but the observation optical system 3 is adjusted with the mold M removed from the mold holding unit 6. May be.

  The dispenser 8 arranges the imprint material R on the shot area of the substrate W. In one example, the dispenser 8 has a nozzle that discharges the imprint material R, and the imprint material R is discharged from the nozzle while the substrate W is scanned and driven by the substrate drive mechanism 20, thereby causing the shot region of the substrate W to be discharged. An imprint material R is disposed. The control unit CNT controls the substrate driving mechanism 20, the mold driving mechanism 30, the curing unit 1, the alignment optical system 2, the observation optical system 3, and the dispenser 8. The control unit CNT is, for example, PLD (abbreviation of Programmable Logic Device) such as FPGA (abbreviation of Field Programmable Gate Array), or ASIC (abbreviation of Application Specific Integrated Circuit) or an ASIC (abbreviation of Generalized Integrated Circuit). It can be constituted by a computer or a combination of all or part of them.

  The imprint apparatus 100 may further include a static elimination mechanism 40 that reduces the charge amount of the mold M. The static elimination mechanism 40 can include, for example, an ionizer. The static elimination mechanism 40 can act to reduce the amount of charge when a member other than the mold M, for example, the reference plate 7 is charged.

  Hereinafter, an imprint process (pattern formation process) for one shot area by the imprint apparatus 100 will be described with reference to FIG. First, as shown in FIG. 4A, the dispenser 8 is driven while the substrate holding unit 5 (substrate W) is driven by the substrate driving mechanism 20 so that the shot area of the substrate W passes below the dispenser 8. Thus, the imprint material R is arranged on the shot area of the substrate W.

  Next, as shown in FIG. 4B, the substrate holding unit 5 is arranged by the substrate driving mechanism 20 so that the shot region where the imprint material R is disposed is disposed below the pattern region Mp of the mold M. (Substrate W) is driven. Next, as shown in FIG. 4C, the relative position between the shot region of the substrate W and the pattern region Mp of the mold M is measured using the alignment optical system 2, and the substrate driving mechanism 20 and the mold driving mechanism 30 are measured. The shot area and the pattern area Mp are aligned with each other. Further, at least one of the substrate driving mechanism 20 and the mold driving mechanism 30 is controlled so that the imprint material R on the substrate W and the pattern region Mp of the mold come into contact with each other. Then, the curing energy is applied to the imprint material R by the curing unit 1, whereby the imprint material R is cured, and a pattern Dp made of the cured imprint material R is formed on the substrate W.

  Next, as shown in FIG. 4D, at least the substrate driving mechanism 20 and the mold driving mechanism 30 are separated so that the pattern Dp made of the cured imprint material R on the substrate W and the mold M are separated. One is controlled. The above imprint process is performed for each of the plurality of shot areas of the substrate W.

  Here, a change in the relative positions of the dispenser 8, the mold M, and the reference plate 7 in the imprint apparatus of the comparative example will be described with reference to FIG. The positions of the dispenser 8 and the mold M are fixed, and the substrate holder 5 moves. In the comparative example, as shown in FIG. 5A, the dispenser 8 is arranged in the first direction (−X direction) DIR1 when viewed from the mold holding unit 6 or the mold M. Further, in the comparative example, the reference plate 7 is viewed from the virtual straight line VL that is parallel to the second direction DIR2 perpendicular to the first direction DIR1 and passes through the center of the substrate holding part 5 or the substrate W, and the virtual straight line VL. It arrange | positions between the edge part E2 of the board | substrate holding | maintenance part in the other side of the 1st direction DIR1.

  In the imprint process for the shot area S11, as shown in FIG. 5B, the shot area S11 is positioned below the dispenser 8 in order to place the imprint material R in the shot area S11. In this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged. Next, as illustrated in FIG. 5C, the substrate holding unit 5 is driven by the substrate driving mechanism 20 so that the shot region S <b> 11 in which the imprint material R is disposed is positioned below the mold M. Even in this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged.

  In the imprint process for the shot area S42, as shown in FIG. 5D, the shot area S42 is positioned below the dispenser 8 in order to place the imprint material R on the shot area S42. In the state of FIG. 5D, since the reference plate 7 is located under the mold M, a discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the mold M can be damaged.

  Hereinafter, changes in the relative positions of the dispenser 8, the mold M, and the reference plate 7 in the imprint apparatus 100 according to the first embodiment of the present invention will be described with reference to FIG. The positions of the dispenser 8 and the mold M are fixed, and the substrate holder 5 moves. In the first embodiment, as shown in FIG. 6A, the dispenser 8 is arranged in the first direction (−X direction) DIR1 when viewed from the mold holding unit 6 or the mold M. In the first embodiment, the reference plate 7 includes a virtual straight line VL that is parallel to the second direction DIR2 perpendicular to the first direction DIR1 and passes through the center of the substrate holding part 5 or the substrate W, and the virtual straight line VL. As viewed, it is arranged between the end E1 of the substrate holding part in the first direction DIR1. Such an arrangement is advantageous for reducing the discharge between the charged mold M and the reference plate 7 and reducing breakage of the reference plate 7, as will be described later.

  Here, the substrate holding unit 5 may have a rectangular shape having two sides parallel to the first direction DIR1 and two sides parallel to the second direction DIR2. The reference plate 7 can be arranged between the rectangular vertex V <b> 1 located on the first direction DIR <b> 1 side when viewed from the virtual straight line VL and the center of the substrate holder 5. The center of the substrate holding part 5 can be the center of gravity of the substrate holding part 5, for example. Such an arrangement is advantageous for reducing the size of the substrate holder 5. In FIG. 6A, the reference plate 7 is disposed between the rectangular vertex V <b> 1 positioned on the first direction DIR <b> 1 side when viewed from the virtual straight line VL and the center of the substrate holder 5. However, the reference plate 7 may be disposed between the other vertex V2 of the rectangular shape located on the first direction DIR1 side when viewed from the virtual straight line VL and the center of the substrate holding unit 5.

  In the imprint process for the shot area S11, as shown in FIG. 6B, the shot area S11 is positioned below the dispenser 8 in order to place the imprint material R in the shot area S11. In this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged. Next, as shown in FIG. 6C, the shot area S <b> 11 in which the imprint material R is arranged is positioned under the mold M. Even in this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged.

  In the imprint process for the shot area S42, as shown in FIG. 6D, the shot area S42 is positioned below the dispenser 8 in order to place the imprint material R in the shot area S42. In this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged. Next, as shown in FIG. 6 (e), the shot region S 42 in which the imprint material R is arranged is positioned under the mold M. Even in this state, the mold M and the reference plate 7 are sufficiently separated from each other, so that no discharge occurs between the charged mold M and the reference mark of the reference plate 7, and the reference plate 7 is not damaged.

  In the first embodiment, since the mold M and the reference plate 7 are sufficiently separated in the imprint process for other shot areas, the charged mold M and the reference mark on the reference plate 7 are separated from each other. No discharge occurs and the reference plate 7 is not damaged.

  Here, as schematically shown in FIGS. 7A and 7B, even when the pattern region Mp of the mold M is positioned with respect to any of the plurality of shot regions of the substrate W, the reference It is preferable that the plate 7 does not face the mold M. Alternatively, it is preferable that the reference plate 7 does not face the peripheral region PR of the mold M when the pattern region Mp of the mold M is positioned with respect to any of the plurality of shot regions of the substrate W.

  7A and 7B, the two shot areas closest to the reference plate 7 are shot areas S41 and S31. FIG. 7A shows a state where the pattern area Mp of the mold M is positioned with respect to the shot area S41. When the distance between the side closest to the reference plate 7 among the four sides of the mold M and the reference plate 7 is D1, D1> 0. FIG. 7B shows a state where the pattern area Mp of the mold M is positioned with respect to the shot area S31. When the distance between the side closest to the reference plate 7 among the four sides of the mold M and the reference plate 7 is D2, D2> 0.

  The control unit CNT controls the driving of the substrate holding unit 5 by the substrate driving mechanism 20 so that the reference plate 7 does not face the mold M between the pattern formation for the first shot region and the pattern formation for the final shot region. . The first shot region is a shot region where a pattern is first formed among a plurality of shot regions of the substrate W, and the last shot region is a shot region where a pattern is formed last among a plurality of shot regions of the substrate W. It is.

  The pattern formation for the first shot region includes at least the arrangement of the imprint material R with respect to the first shot region, the contact between the imprint material R and the mold M in the first shot region, and the imprint material R in the first shot region. Including curing. Here, after the imprint material R is arranged on all or a part of the other shot regions among the plurality of shot regions, the imprint material R is arranged continuously with the process of arranging the imprint material R on the first shot region. The imprint material R in one shot area and the mold M may be contacted.

  In the calibration described with reference to FIGS. 2 and 3, the mark on the reference plate 7 is imaged (observed) through the mold M by the alignment optical system 2 or the observation optical system 3. Therefore, the reference plate 7 is disposed so as to face the mold M. Such a calibration can be performed after the charge amount of the mold M is reduced by the static elimination mechanism 40.

  On the other hand, in the imprint process for a plurality of shot regions of the substrate W, if the gap between the charged mold M and the substrate W is maintained, the effect of charge removal by the charge removal mechanism 40 cannot be sufficiently obtained. Therefore, widening the gap between the mold M and the substrate W during the imprint process for a plurality of shot regions of the substrate W can be one method for enhancing the effect of static elimination. However, in such a method, productivity can be reduced.

  In the imprint method implemented using the imprint apparatus 100 described above, the imprint material R is arranged by the dispenser 8 for each of the plurality of shot regions of the substrate W, and the mold M is brought into contact with the imprint material R. Including a process of curing. From the start to the end of this process, the substrate holder 5 can be driven so that the reference plate 7 does not face the mold M.

  According to the first embodiment, it is possible to reduce the possibility of damage to the reference plate 7 while reducing the necessity for static elimination.

  Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment can be implemented together with the first embodiment or independently of the first embodiment. Matters not particularly mentioned in the second embodiment can follow the first embodiment.

  First, the reference plate 7 of the comparative example will be described with reference to FIGS. However, the reference plate 7 of the comparative example described with reference to FIGS. 8 and 9 can be applied to the first embodiment. The reference plate 7 may have a plurality of reference marks including reference marks 12 and 13. The base material of the reference plate 7 is not easily deformed by heat and can be made of a stable material (for example, quartz). The reference marks 12 and 13 are a portion (shaded portion) where the base material is covered with a plurality of conductive reflection portions CR made of a conductive material film (for example, a chromium film) that reflects light, and a portion where the base material is exposed (white). And a cut-out portion). The plurality of conductive reflecting portions CR can be formed of, for example, a single layer or multiple layers of conductive material. Note that all or some of the plurality of conductive reflecting portions CR may be electrically connected to each other.

  Here, as shown in FIG. 8, a case is considered where at point P, two or more adjacent conductive reflectors CR are in point contact. In this case, as shown in FIG. 9, in the state where the charged mold M faces the reference plate 7, electrostatic induction is caused by the charge 15 of the mold M, and the charge on the conductive reflection portion CR of the reference plate 7 is Can move. In FIG. 9, the charge 15 charged in the mold M is a negative charge, and the charge 16 on the conductive reflecting portion CR of the reference plate 7 is a positive charge. However, these may be reversed depending on conditions. If there is a point P on the path of the charge 16 that moves on the conductive reflector CR due to electrostatic induction, the charge may concentrate on the point P and the reference mark may be damaged.

  FIG. 10 shows an example of the reference plate 7 of the second embodiment. FIG. 11 shows another example of the reference plate 7 of the second embodiment. In the second embodiment, the reference marks 12 and 13 include a plurality of conductive reflection portions CR, and the plurality of conductive reflection portions CR are arranged so as not to make point contact with each other. In the example of FIG. 11, a round shape is adopted for a part of the plurality of conductive reflecting portions CR. A round shape may be adopted for all of the plurality of conductive reflecting portions CR.

  Here, a mode in which a minute line is broken by discharge is considered. The discharge breakdown can occur when the in-plane distribution of the charge Q accumulated on the reflective reflector CR is changed by facing the charged mold M. When the in-plane distribution of the charge Q changes, the charge Q moving through the minute line generates a large amount of Joule heat in the vicinity of the minute line having the highest resistance. If the accumulated Joule heat exceeds the melting point of the conductive reflecting portion CR, the minute line is melted and the reference mark is damaged. If the temperature rise due to Joule heat in the minute line portion is Temp, the temperature rise Temp can be given by (1).

Temp = A · ρ _e · Q ² / (d ² · W ² · ρ · c · t) (1)
Here, ρ _e is the volume resistivity of the conductive reflector CR, Q is the charge flowing through the conductive reflector CR, and d is the thickness of the conductive reflector CR. W is the line width of the path through which the charge Q flows, ρ is the density of the conductive reflector CR, c is the specific heat of the conductive reflector CR, t is the time during which the charge Q flows, and A is a unit conversion constant.

  As a result of examining how much charge is moving in the configuration of FIG. 5, it has been found that the charge of 1 to 50 pC moves within several ms. In a chromium film having a thickness of 100 nm, when a charge of 50 pC flows in a line having a width of 180 nm in 1 ms, a temperature rise exceeding 1907 ° C., which is the melting point of chromium, occurs. Since the temperature rise is inversely proportional to the square of the line width w, the line width may be at least 57 nm or more. Here, a line width of 214 nm or more with a fourfold likelihood is preferable, and a line width of 570 nm or more with a tenfold likelihood is more preferable.

  The third embodiment of the present invention will be described below with reference to FIG. The third embodiment can be implemented together with the first and / or second embodiment or independently of the first and second embodiments. Matters not particularly mentioned in the third embodiment can follow the first and / or second embodiment.

  The reference plate 7 according to the third embodiment includes one or more conductive reflecting portions CR and a transparent conductive film TM that covers the one or more conductive reflecting portions CR. The transparent conductive film TM can be composed of, for example, an ITO film, an IZO film, a TNO film, an Al thin film, or the like. The transparent electrode film TM can be made of other various materials as long as the observation of the reference marks 12 and 13 of the reference plate 7 is not hindered. The transparent conductive film TM can be electrically connected to a member having a predetermined potential such as a ground in the imprint apparatus, but may be floating. By providing the transparent conductive film TM, even if the charge distribution is instantaneously formed, the charge flows on the surface of the transparent conductive film TM and does not flow through the conductive reflecting portion CR constituting the reference marks 12 and 13.

  In one example, the conductive reflecting portion CR of the reference plate 7 has the configuration shown in FIG. 8 and is configured by a single chrome layer having a thickness of 100 nm, and the transparent electrode film TM is an ITO having a thickness of 200 nm. Consists of a membrane. Although a step is formed by the chromium film, the resistance value of the transparent electrode film TM can be sufficiently reduced by setting the thickness of the transparent conductive film TM to 200 nm. The light transmittance of the ITO film is 70% or more when the reference mark is observed with light having a wavelength of 450 nm. In this example, it was confirmed that the reference mark could be observed by the alignment optical system 2 and the observation optical system 3 without causing damage to the reference mark. The conductive reflecting portion CR of the reference plate 7 may have the configuration shown in FIG.

  The pattern of the cured product formed using the imprint apparatus 100 is used permanently on at least a part of various articles or temporarily used when manufacturing various articles. The article is an electric circuit element, an optical element, a MEMS, a recording element, a sensor, or a mold. Examples of the electric circuit elements include volatile or nonvolatile semiconductor memories such as DRAM, SRAM, flash memory, and MRAM, and semiconductor elements such as LSI, CCD, image sensor, and FPGA. Examples of the mold include an imprint mold.

  The pattern of the cured product is used as it is as a constituent member of at least a part of the article or temporarily used as a resist mask. After etching or ion implantation or the like is performed in the substrate processing step, the resist mask is removed.

  Next, an article manufacturing method will be described in which a pattern is formed on a substrate by the imprint apparatus 100, the substrate on which the pattern is formed is processed, and an article is manufactured from the processed substrate. As shown in FIG. 13A, a substrate 1z such as a silicon wafer on which a workpiece 2z such as an insulator is formed is prepared. Subsequently, the substrate 1z is formed on the surface of the workpiece 2z by an inkjet method or the like. A printing material 3z is applied. Here, a state is shown in which the imprint material 3z in the form of a plurality of droplets is applied on the substrate.

  As shown in FIG. 13B, the imprint mold 4z is opposed to the imprint material 3z on the substrate with the side having the concave / convex pattern formed thereon. As shown in FIG. 13C, the substrate 1 provided with the imprint material 3z is brought into contact with the mold 4z, and pressure is applied. The imprint material 3z is filled in a gap between the mold 4z and the workpiece 2z. In this state, when light is irradiated as energy for curing through the mold 4z, the imprint material 3z is cured.

  As shown in FIG. 13D, after the imprint material 3z is cured, when the mold 4z and the substrate 1z are separated, a pattern of a cured product of the imprint material 3z is formed on the substrate 1z. This cured product pattern has a shape in which the concave portion of the mold corresponds to the convex portion of the cured product, and the concave portion of the mold corresponds to the convex portion of the cured product, that is, the concave / convex pattern of the die 4z is transferred to the imprint material 3z. It will be done.

  As shown in FIG. 13 (e), when etching is performed using the pattern of the cured product as an etching resistant mask, the portion of the surface of the workpiece 2z where there is no cured product or remains thin is removed, and the groove 5z and Become. As shown in FIG. 13 (f), when the pattern of the cured product is removed, an article in which the groove 5z is formed on the surface of the workpiece 2z can be obtained. Although the cured product pattern is removed here, it may be used as, for example, a film for interlayer insulation contained in a semiconductor element or the like, that is, a constituent member of an article without being removed after processing.

100: imprint apparatus, 2: alignment optical system, 3: observation optical system, 7: reference plate, 12, 13: reference mark, W: substrate, M: mold

Claims (15)

An imprint apparatus that forms a pattern on the substrate by bringing a mold into contact with the imprint material disposed on the substrate and curing the mold,
A mold holding unit for holding the mold;
A substrate holder for holding the substrate;
A dispenser for disposing an imprint material on the substrate;
A scope for imaging the mark,
The substrate holding unit includes a reference plate having a reference mark imaged by the scope, and the dispenser is disposed in a first direction as viewed from the mold holding unit, and the reference plate is in the first direction. Between a virtual straight line parallel to the second direction perpendicular to the center and passing through the center of the substrate holding part, and an end of the substrate holding part on the first direction side when viewed from the virtual straight line. Yes,
An imprint apparatus characterized by that. The substrate holding part has a rectangular shape having two sides parallel to the first direction and two sides parallel to the second direction, and the reference plate is Arranged between a vertex located on one side and the center,
The imprint apparatus according to claim 1. Forming a pattern for a first shot region where a pattern is first formed among a plurality of shot regions of the substrate, and forming a pattern for a final shot region where a pattern is formed last among the plurality of shot regions of the substrate; The substrate holder is driven so that the reference plate does not face the mold during
The imprint apparatus according to claim 1, wherein the imprint apparatus according to claim 1. The pattern formation for the first shot region includes at least the placement of the imprint material for the first shot region, the contact between the imprint material for the first shot region and the mold, and the imprint for the first shot region. Including hardening of the material,
The imprint apparatus according to claim 3. The mold includes a pattern region having a pattern to be transferred to an imprint material disposed on the substrate,
Even when the pattern region is positioned with respect to any of the plurality of shot regions of the substrate, the reference plate does not face the mold,
The imprint apparatus according to claim 1, wherein the apparatus is an imprint apparatus. The mold includes a peripheral region surrounding a pattern region;
Even when the pattern region is positioned with respect to any of the plurality of shot regions of the substrate, the reference plate does not face the peripheral region of the mold,
The imprint apparatus according to claim 5. A static elimination mechanism for reducing the charge amount of the mold;
The process in which the scope images the reference plate through the mold is performed after the charge amount of the mold is reduced by the static elimination mechanism.
The imprint apparatus according to claim 1, wherein the apparatus is an imprint apparatus. The reference mark includes a plurality of conductive reflection portions, and the plurality of conductive reflection portions are arranged so as not to make point contact with each other.
The imprint apparatus according to claim 1, wherein the imprint apparatus is any one of claims 1 to 7. The reference mark has a transparent conductive film that covers the plurality of conductive reflective portions.
The imprint apparatus according to claim 8. The reference mark has a conductive reflection portion and a transparent conductive film covering the conductive reflection portion.
The imprint apparatus according to claim 1, wherein the imprint apparatus is any one of claims 1 to 7. An imprint apparatus that forms a pattern on the substrate by bringing a mold into contact with the imprint material disposed on the substrate and curing the mold,
A mold holding unit for holding the mold;
A substrate holder for holding the substrate;
A dispenser for disposing an imprint material on the substrate;
A scope for imaging the mark,
The substrate holding part includes a reference plate having a reference mark imaged by the scope, the reference mark includes a plurality of conductive reflection parts, and the plurality of conductive reflection parts are not in point contact with each other. Arranged,
An imprint apparatus characterized by that. An imprint apparatus that forms a pattern on the substrate by bringing a mold into contact with the imprint material disposed on the substrate and curing the mold,
A mold holding unit for holding the mold;
A substrate holder for holding the substrate;
A dispenser for disposing an imprint material on the substrate;
A scope for imaging the mark,
The substrate holding part includes a reference plate having a reference mark imaged by the scope, and the reference mark includes a conductive reflection part and a transparent conductive film covering the conductive reflection part.
An imprint apparatus characterized by that. A step of forming a pattern on a substrate by the imprint apparatus according to any one of claims 1 to 12, and a step of processing the substrate on which the pattern has been formed in the step. An article manufacturing method comprising manufacturing an article from the processed substrate. An imprint method for forming a pattern on a substrate by bringing the mold into contact with an imprint material disposed on the substrate held by the substrate holding unit having a reference plate and curing the mold,
Disposing an imprint material by a dispenser for each of a plurality of shot regions of the substrate, and performing a process of bringing the mold into contact with the imprint material and curing it;
From the start to the end of the process, the substrate holder is driven so that the reference plate does not face the mold.
An imprint method characterized by the above. The dispenser is disposed in a first direction when viewed from a mold holding unit that holds the mold, and the reference plate is parallel to a second direction perpendicular to the first direction and is centered on the substrate holding unit. Disposed between a virtual straight line passing through and an end of the substrate holding part on the first direction side when viewed from the virtual straight line,
The imprint method according to claim 14.

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